600MW燃煤机组发生风煤交叉闭锁分析

Analysis of the Wind-coal Cross Blocking in the 600MW Coal-fired Units

介绍了600MW燃煤机组在加减负荷控制中,由于二次调频范围较大,氧量修正延时造成风量仍在增大,煤量跟随增加,引发风煤交叉闭锁,燃料超调,负荷、主汽压、汽温、燃料量、给水量等参数失常,威胁机组安全运行的异常情况。通过分析与总结,提出了通过调整汽机数字式电液控制系统的汽机转速测量回路的滤波电容量、放宽风量对煤量的限制、增加风煤水交叉限制动作过程报警等措施来提前预防风煤交叉闭锁现象。一旦发生风煤交叉闭锁,可以通过偏置燃料控制站或者退出机组协调控制等手段进行手动干预,控制好煤和水,确保机组安全运行。

In the 600 MW coal-fired units control system, the secondary frequency modulation has a wide range while the active power is increasing or decreasing, always the delay of the oxygen correction will cause air volume as well as the coal consumption increasing, then the wind-coal cross blocking, the parameters such as the fuel control beyond range, active power, main steam pressure.steam temperature.fuel quantity.feedwater flow will out of control, and it will threat unit safe operation. Through the analysis and summary, this article put forward some preventions of wind-coal cross blocking phenomenon, such as adjusting the turbine digital electro-hydraulic control system of the turbine speed measuring loop filter capacitance.relaxing the volume of coal quantity limit,adding alarm in the process of the wind-coal cross blocking, etc. If the wind coal cross blocking happens, this paper provide manual intervention measures such as offset the fuel control station and exit unit coordinated control system to control the coal consumption and feedwater flow and ensure the safe operation of the unit.